This was sent to me by a reader. It is from the Melian Dialogue by Thucydides.

Athens (then the big bully on block) wanted control over the little island of Melos as a strategic asset in its quarrel with Sparta. It gave the Melians an ultimatum: either submit to Athenian control or face annihilation.

The Melians chose defiance. They were crushed. Those men captured were slaughtered. The women and children were sold into slavery. But the Athenian treatment of the Melians caused horror across the Greek world; it marked the moment of Athenian overreach and the beginning of their decline, as vulnerable city states allied with Sparta to protect themselves. Athenian arrogance backfired disastrously. In the end, Melian exiles retook their island.

Here is an abridged dialogue between the Athenian envoys and the Melian council. (Thucydides was an Athenian general, but viewed the Melians as the victims of this saga.)